Automatically aerated leaching field system

ABSTRACT

A sewage system comprising a septic tank, an air vented distribution chamber, and a leaching field formed of an array of air vented leaching canals. The flow of effluent from the distribution chamber into each leaching canal can be controlled from above ground. Air can be forced through the system by incorporating fans at the vents of the distribution chamber and leaching canals. By properly cycling the flow of air with the flow of effluent, a more efficient and longer lasting leaching field system with less pollution of nearby soil and water results, due to improved aerobic action, increased evaporation, and benefits from total drying of each canal.

United States Patent Flynn Oct. 17, 1972 [5 AUTOMATICALLY AERATED2,362,747 11/1944 Duke ..61/ 12 LEACHING FIELD SYSTEM 3,425,226 2/1969Santeford, Jr. 61/13 Inventor: J F. F y Strawberry Berthold 3 Road,Concord, Mass. 01742 [22] Filed: Feb. 1, 1971 [21] App1.No.: 111,209

[52] U.S.C1. ..6l/l1,2l0/176,210/532, 251/128 [51] Int. Cl. ..E02b11/00, BOld 21/10,C02c 1/18 [58] Field of Search ..61/11, 13, 12, 10;210/121, 210/73,259, 170, 7, 4,532 S; 137/600; 251/128 [56] ReferencesCited UNITED STATES PATENTS 924,285 6/1909 Smith ..210/532 S 1,795,1233/1931 Harris ..210/532 S 2,944,669 7/1960 Schaaf ..61/13 X 1,408,5483/1922 Trowbridge ..61/11 2,432,887 12/1947 Haviland ..210/121 PrimaryExaminer-Jacob Shapiro Attorney-Russell & Nields [57] ABSTRACT A sewagesystem comprising a septic tank, an air vented distribution chamber, anda leaching field formed of an array of air vented leaching canals. Theflow of effluent from the distribution chamber into each leaching canalcan be controlled from above ground. Air can be forced through thesystem by incorporating fans at the vents of the distribution chamberand leaching canals. By properly cycling the flow of air with the flowof effluent, a more efficient and longer lasting leaching field systemwith less pollution of nearby soil and water results, due to improvedaerobic action, increased evaporation, and benefits from total drying ofeach canal.

11 Claims, 4 Drawing Figures PATENTEflum 17 m2 JOHN F. FLYNN BY W MATTORNEYS AUTOMATICALLY AERATED LEACHING FIELD SYSTEM BACKGROUND OF THEINVENTION l. Field of the Invention This invention relates to sewagesystems; more specifically, the invention is concerned with sewagesystems comprising a septic tank, a distribution chamber and leachingcanals.

2. Prior Art In a sewage system of this type, the sewage first enters aseptic tank where solids settle out to be partially decomposed. Theeffluent, composed basically of liquids but containing some solids,drains off into a distribution chamber and is there distributed throughconnecting pipes into leaching canals where further decomposition byaerobic or bacterial action takes place. Most of the effluent thenseepsinto the ground.

The major probelm with this arrangement is that occasionally and forvarying reasons the leaching field is unable to dispose of the amount ofeffluent flowing into it: the surrounding ground may become saturated;the canals may become clogged with solids; or the intake may simply betoo great for the size of the leaching filed. For example, clay-typesoil is a particularly poor absorber of water; a leaching field in suchsoil is relatively expensive and inefficient since a relatively largefield must be employed. As another example, a dual problem is presentedby grease contained in the effluent, which often stems from the use ofdetergents. The grease not only tends to coat the bottom of the leachingcanal but also affects the porosity of the soil into which it flows.When the accumulated grease causes clogging it becomes necessary tophysically enter and clean out the clogged canal.

In addition, effluent absorbed into the ground during the course ofcontinuous charging of the leaching canals gradually spreads through thesurrounding soil and can leak into and pollute nearby lakes and rivers.

SUMMARY The basic objects of this invention are the provision of meansfor improving the effluent handling capability of a given leaching fieldwhile avoiding the problems of effluent disposal and pollution found inthe prior art. These objects are accomplished by providing means forincreasing the rate of both effluent evaporation and of aerobic actionon the effluent, and by providing means for totally drying any selectedcanal and the soil in its immediate vicinity. Among other benefits, thedetrimental effect of the grease contained within the effluent isalleviated.

In the accomplishment of these objects, air is forcibly circulatedthroughout at least a selected portion of the system; as an example, thepreferred embodiment contains fans at filtered vents of the leachingcanals and distribution chamber. 'In practice, the positioning and sizeof the fans are dependent upon the size of the leaching field and rateof evaporation required.

In addition to the use of forced air, the flow of effluent to each canalcan be regulated as desired. For example, one or more connecting pipesmay be lifted above the level of effluent in the distribution chamber,shutting off effluent flow to the associated canals. Alternatively, thedesired regulation may be obtained by placing an individually adjustableblocking element within each connecting pipe.

In operation of the system, the flow of effluent to at least one canalis shut off, while flow to the remainder of the field is maintained.Forced air is caused to flow through the canal which has been shut off.The forced air flowing over the effluent increases evaporation, aids inaerobic action in the effluent, and eventually dries both the residuesolids of the effluent in the shut-off canal and the soil immediatelysurrounding the canal. Once dried, the forced air can be discontinued,the canal returned to normal flow, and another canal cycled through thedrying procedure.

This system therefore not only enables increased evaporation of andaerobic action on the effluent, but also eliminates the detrimentaleffects of the grease present in the effluent. As the residue solids dryin the shut-off canal, the grease dries into a flake-like substancewhich is washed away by the next inflow of effluent, thereby removingthe grease coating on the bottom of the canal.

BRIEF DESCRIPTION OF THE DRAWINGS The invention may be best understoodfrom the following detailed description thereof having reference to theaccompanying drawings in which:

FIG. 1 is a top view of a sewage system with vented distribution chamberand a leaching field of three vented leaching canals;

FIG. 2 is a side view in cross-section of the sewage system of FIG. 1,taken along line 2-2;

FIG. 3 is an expanded view in cross-section of a distribution chamberand one embodiment of control mechanism.

FIG. 4 is a fragmentary view in cross-section of another embodiment ofcontrol mechanism.

DETAILED DESCRIPTION OF THE INVENTION With reference to FIGS. 1 and 2, asewage system utilizing the invention is illustrated comprising first aseptic tank 1, a distribution chamber 2, leaching canals 3, andflow-control mechanisms indicated at 4. Although three leaching canalsare shown, any number might be used, according to the needs of theparticular system. As in a typical sewage system, sewage flows through asewer pipe 5 into the septic tank 1, where decomposition begins and many:solids settle out. Effluent, comprised generally of liquids, flows fromthe septic tank 1 through a sewage pipe 6 to the distribution chamber 2.There it is distributed among connecting pipes 7 protruding into theinterior of the chamber, and flows past control mechanisms 4 to theleaching canals 3. The effluent continues to be subjected to bacterialand aerobic action in the leaching canals, where some of the effluentevaporates and the remainder is absorbed into the surrounding soil.

The canals 3 and distribution chamber 2 are vented by air vents 8 withcarbon filters 9 to remove noxious fumes.

Electric fans 10 and 11 are provided within the system to forciblycirculate air. In a preferred embodiment, as shown in FIG. 2, exhaustfans 10 are positioned at the vents 8 of the canals; an intake fan 11 ispositioned at the vent 8 of the distribution chamber 2. Electricalwiring l2 and a switch. box 13 control the fans. Of course it ispossible to change the orientation of the fans, as by mounting theintake fan 1 l on a shelf as shown in FIG. 3 and directing it onto theinlet of a connecting pipe 7.

With more particular reference to FIG. 3, the control mechanism,indicated at 4, contains means for regulating the flow of effluent fromthe distribution chamber 2 to a canal 3. In a preferred embodiment thiscontrol mechanism includes a sleeve pipe 14, formed of cast iron orsteel, surrounding each connecting pipe 7. A gate box 15 is placed atopthe sleeve pipe 14, and covered by an access manhole 16. An adjustingrod 17 is attached to the connecting pipe 7 through an opening in thesleeve pipe 14, and is removably fastened to adjusting hooks 18.

The connecting sewer pipe 7 can then be vertically adjusted a desireddistance; in the preferred embodiment approximately 2 inches of freetravel are obtained by having the inside diameter of the sleeve pipe 14at least two inches wider than the outside diameter of the connectingpipe 7. This two inch free travel enables the connecting pipe 7 to bepulled out of the effluent, shutting off the flow of effluent to theassociated leaching canal. A depending tab 19 at that end of the sewerpipe 7 within the distribution chamber 2 prevents leakage into thesleeve pipe 14. Each connecting pipe is provided with a controlmechanism such as the one indicated at 4. A baffle 20 comprising avertical slab of concrete or other convenient material may be placednear the entrance of the sewage pipe 6 into the distribution chamber 2to limit effluent motion within the distribution chamber should a surgeof effluent be received. Instead of lifting a connecting pipe 7 out ofthe effluent to shut off effluent flow to a leaching canal 3, aneffluent blocking element 21 may be placed directly inside theconnecting pipe 7 as shown in FIG. 4. The bottom of the element 21 isrounded to conform to the curve at the bottom of the connecting pipe 7.It is held at the end of the adjusting rod 17, which extends through ahole in the pipe. Effluent flow is controlled by moving the blockingelement 20 up or down or by turning it sideways. The connecting pipe 7remains stationary, and sleeve pipes are not needed.

The leaching canals operate in either of two modes: a normal mode, or adrying mode. In the normal mode effluent flows into the canal, and theexhaust fan 10 of that canal is off. In the drying mode, the flow ofeffluent into a canal is shut off at the control mechanism 4 of thatcanal, and the exhaust fan 10 of that canal is on. When any exhaust fan10 of any canal is on, the intake fan 11 in the distribution chamber 2is also on.

The operational cycle of the preferred embodiment consists of one canalbeing in a normal mode with the other two canals in a drying mode. Oncea canal is dry, it is placed in a normal mode and the canal previouslyin a normal mode is changed to a drying mode. In the case of a steadyintake of effluent into the distribution chamber 2, this operationalcycle could run continuously with, at a given time, one canal in thenormal mode and the remaining canals in the drying mode.

Of course, a particular advantage of this system is that the cycling canbe adjusted to meet differing needs of the system by changing the fanoperation or the distribution of sewage among canals. If, for example,the intake of effluent is relatively slow, the cycling could beinterrupted for a time by turning off the fans. In the same situation oflow intake, it might be desireable to feed two canals at a time whiledrying only one. In a situation where more effluent must be handled,e.g., if the soil becomes saturated or if there is simply a higherinput, other cycles could be used: the exhaust fans in the canal atnormal mode could also be running, increasing evaporation and providingmore air for aerobic action in the effluent. In any case, the placementand power of the fans are dependent upon the needs of the system. Forexample, if more effluent must be handled, more powerful fans, with morevents, might be needed. Conversely, if less effluent must be handled,less powerful fans or even no exhaust fan could be used.

Means of control other than the two mechanisms indicated at 4 in FIGS. 3and 4 could be readily used. For example, electrically controlled gatevalves could be placed in the connecting pipes 7, and a simple timingmechanism used to run the canals and fans through the cycles.

During the drying cycle not only the leaching canal itself but also theimmediately surrounding soil is dried, removing the danger of soilsaturation. This advantage is most important for soils with poor waterabsorption characteristics, such as clays. In addition, drying the soileliminates or at least retards the tendency of effluent to spread outfrom the leaching canal and pollute nearby water sources. The presentinvention is particularly useful when employed in connection withlaterally vented leaching canals as described in my copendingapplication Ser. No. 831,881, filed June 10, 1969. No limitation to thattype of leaching canal is intended, however, as the present invention iseffective for other leaching canals also.

Having thus described the principles of the invention together withseveral illustrative embodiments thereof, it is understood that,although specific terms are employed, they are used in a generic anddescriptive sense, and not for the purpose of limitation, the scope ofthe invention being set forth in the following claims.

Iclaim:

1. A sewage disposal system comprising a distribution chamber and aplurality of leaching canals, said leaching canals stemming from saiddistribution chamber, control means for selectively intercepting theflow of sewage, but not the flow of air, between said distributionchamber and one or more of said leaching canals and diverting saidsewage flow to the other canals, and means for promoting air flowthrough intercepted canals.

2. The sewage disposal system of claim 1 wherein said control meanscomprises connecting pipes between said distribution chamber theentrance to and each of said leaching canals, each said connecting pipebeing vertically adjustable whereby the flow of sewage to a leachingcanal may be intercepted by an upward adjustment of the correspondingconnecting pipe.

3. A sewage disposal system comprising a distribution chamber and aplurality of leaching canals, said leaching canals stemming fromdistribution chamber, and control means for selectively shutting off theflow of sewage to one or more of said leaching canals and diverting saidsewage flow to the canals not shut off, said control means comprisingconnecting pipes between said distribution chamber and each of saidleaching canals, each said connecting pipe containing a moveable sewageblocking element conforming to the bottom portion thereof which may bepositioned to shut off the flow of sewage through said pipe.

4. The sewage disposal system of claim 1 wherein said air flow promotingmeans comprise means for circulating airthrough a leaching canal towhich the flow of sewage has been intercepted, whereby liquid is removedfrom said canal by evaporation into said circulated air, saidcirculating means including at least one air vent at each leaching canaland at least one vent at the distribution camber.

S. The sewage disposal system of claim 4 further defined as includingmeans for moving air by force through said leaching canals bycirculation between said vented distribution chamber and said leachingcanal vents.

6. A sewage disposal system comprising a distribution chamber, aplurality of leaching canals, said leaching canals stemming from saiddistribution chamber, control means for adjusting the relativedistribution of sewage among said leaching canals, at least one air ventat each leaching canal and at least one vent at the distributionchamber, and at least one fan within said leaching field for moving airby force through at least a portion of said leaching field.

7. A sewage disposal system comprising a distribution chamber, aplurality of leaching canals, at least one air vent at each leachingcanal and at the distribution chamber, means for controlling the flow ofsewage to each canal, and means for moving air by force through at leasta portion of said leaching field, said means for moving air by forcecomprising an exhaust fan at each said air vent of a canal and an intakefan at each said air vent of said distribution chamber.

8. In a leaching field system having a plurality of leaching canalsstemming in parallel from a distribution chamber, a method forincreasing the sewage effluent handling capacity of said system whilereducing its polluting effect on nearby soil and water comprising:directing sewage effluent into some of said leaching canals whilecutting off effluent flow into the remaining leaching canals, dryingeach of said cut off canals, and periodically alternating the leachingcanals to which effluent is directed and the leaching canals undergoingdrying.

9. In a leaching field system having a plurality of leaching canalsstemming from a distribution chamber, a method for increasing the sewageeffluent handling capacity of said system while reducing its pollutingeffect on nearby soil and water comprising directing sewage effluentinto some of said leaching canals while cutting off effluent flow intothe remaining leaching canals, circulating airthrough air vents providedin each of said leaching canals and in said distribution chamber, dryingeach of said cut off leaching canals by evaporation of effluent thereininto said circulated air, and periodically alternating the leachingcanals to which effluent is directed and the leaching canals undergoingdrying.

10. The sewage disposal system of claim 5 wherein said means for movingair comprises at least one fan within each of said leaching canals.

11. The sewage disposal system of claim 2, wherein each connecting pipeis provided at the distribution box end with a downwardly depending tabadapted to prevent the flow of sewage under said pipe when said pipe isadjusted upwardly.

1. A sewage disposal system comprising a distribution chamber and aplurality of leaching canals, said leaching canals stemming from saiddistribution chamber, control means for selectively intercepting theflow of sewage, but not the flow of air, between said distributionchamber and one or more of said leaching canals and diverting saidsewage flow to the other canals, and means for promoting air flowthrough intercepted canals.
 2. The sewage disposal system of claim 1wherein said control means comprises connecting pipes between saiddistribution chamber the entrance to and each of said leaching canals,each said connecting pipe being vertically adjustable whereby the flowof sewage to a leaching canal may be intercepted by an upward adjustmentof the corresponding connecting pipe.
 3. A sewage disposal systemcomprising a distribution chamber and a plurality of leaching canals,said leaching canals stemming from distribution chamber, and controlmeans for selectively shutting off the flow of sewage to one or more ofsaid leaching canals and diverting said sewage flow to the canals notshut off, said control means comprising connecting pipes between saiddistribution chamber and each of said leaching canals, each saidconnecting pipe containing a moveable sewage blocking element conformingto the bottom portion thereof which may be positioned to shut off theflow of sewage through said pipe.
 4. The sewage disposal system of claim1 wherein said air flow promoting means comprise means for circulatingair through a leaching canal to which the flow of sewage has beenintercepted, whereby liquid is removed from said canal by evaporationinto said circulated air, said circulating means including at least oneair vent at each leaching canal and at least one vent at thedistribution chamber.
 5. The sewage disposal system of claim 4 furtherdefined as including means for moving air by force through said leachingcanals by circulation between said vented distribution chamber and saidleaching canal vents.
 6. A sewage disposal system comprising adistribution chamber, a plurality of leaching canals, said leachingcanals stemming from said distribution chamber, control means foradjusting the relative distribution of sewage among said leachingcanals, at least one air vent at each leaching canal and at least onevent at the distribution chamber, and at least one fan within saidleaching field for moving air by force through at least a portion ofsaid leaching field.
 7. A sewage disposal system comprising adistribution chamber, a plurality of leaching canals, at least one airvent at each leaching canal and at the distribution chamber, means forcontrolling the flow of sewage to each canal, and means for moving airby forcE through at least a portion of said leaching field, said meansfor moving air by force comprising an exhaust fan at each said air ventof a canal and an intake fan at each said air vent of said distributionchamber.
 8. In a leaching field system having a plurality of leachingcanals stemming in parallel from a distribution chamber, a method forincreasing the sewage effluent handling capacity of said system whilereducing its polluting effect on nearby soil and water comprising:directing sewage effluent into some of said leaching canals whilecutting off effluent flow into the remaining leaching canals, dryingeach of said cut off canals, and periodically alternating the leachingcanals to which effluent is directed and the leaching canals undergoingdrying.
 9. In a leaching field system having a plurality of leachingcanals stemming from a distribution chamber, a method for increasing thesewage effluent handling capacity of said system while reducing itspolluting effect on nearby soil and water comprising directing sewageeffluent into some of said leaching canals while cutting off effluentflow into the remaining leaching canals, circulating air through airvents provided in each of said leaching canals and in said distributionchamber, drying each of said cut off leaching canals by evaporation ofeffluent therein into said circulated air, and periodically alternatingthe leaching canals to which effluent is directed and the leachingcanals undergoing drying.
 10. The sewage disposal system of claim 5wherein said means for moving air comprises at least one fan within eachof said leaching canals.
 11. The sewage disposal system of claim 2,wherein each connecting pipe is provided at the distribution box endwith a downwardly depending tab adapted to prevent the flow of sewageunder said pipe when said pipe is adjusted upwardly.